In the middle of an SPD run I just had sudden vacuum loss with a strange sound coming from near the mantle. I was about halfway through my heads when my system fogged up. After quickly turning off my pump and mantle, I figured glass had cracked somewhere, but I can’t seem to find any cracks. Isn’t a glass failure usually much more violent and dramatic? Here’s a pic of my setup before I removed the bf from the mantle.
On the bottom.of the bf?
Gl fitting cracked?
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Also just found a packing ring in my heads flask… I’ll check GL fittings now.
All GL fittings look fine, as does the BF. I’ll remove the Teflon sleeves to see if anything cracked there.
check the RBF temp probe adapter oRing
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How fast did it lose vacuum? Did you hear in hissing back to atmosphere?
It was instant. I happened to be looking at the gauge when it happened. The Orings look fine as well. I can’t seem to find wtf this was. I’m wondering how to go about putting everything back together. Just wipe the joints with acetone before reassembly and slowly pull vac again?
My pump is running 25 microns blanked off, which I kind of expected with all the volatiles I just pulled, so I don’t think it’s the pump.
yeah see if you can even get it down, also for saftey sake, put a piece of cardboard or something to act as a blast shield between you and the system as you attempt to pump down. if id does pump down, and there is a failure somewhere in the systems glass, thats when its going to implode.
might be overkill but better safe then sorry when your troubleshooting something like this.
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Awesome, thanks for the tip. That’s what I was worried about when putting it back together, the blast shield is a good call.
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For it to be so instant though I’m thinking @RockSteady might be right with the O-rings. Maybe the bf one slipped, which would explain the packing ring ending up in the flask from the pressure. I’ve never heard of cracked glass causing such a dramatic pressure increase.
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replace them if you can, if had them fail on me a few times. look for small cracks or cuts in them.
also make sure they are concentric in the adapter
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Yea, I’ll have to replace it it looks like. Only getting down to 200 microns and I can hear it hissing from there. Looks like I’ll be finishing this run blind on the BF temp and just plug the hole with a glass stopper. At least it wasn’t my head probe adapter.
These ones are from Chemglass. Any suggestions on something more reliable?
best imo is a thermowell they are starting to become more common, measure your flask and search for the size you need, you should be able to find one pretty easily, they are cheap on ebay too.
this one may not be the right length, but something like https://www.acrossinternational.com/Ai-24-40-Glass-Thermowell-w-Viton-Gasket-for-2L-5L-10L-System-SP-Thermowell.htm
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Dude, thanks a ton. I’ll take some measurements and order one after this run. 
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I have ptfe thermometer adapters cause they hold better seal on Chinese glass
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to each their own, PTFE adapters have 2 potential failure/leak points, ie the 24/40 taper and the oring. the thermowells just have the 24/40 taper. I hate having to change orings ever 5 runs lol
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